In recent years, the use of surface-mounted (SMT) connectors for interconnecting circuit boards has grown, because of the ease of electrical connection to elements on the circuit board, the high packaging density of contacts and other advantages. An SMT connector is electrically connected to a circuit board by soldering a soldering part (tine part) of a contact of the connector to a pad on the surface of the circuit board. Some SMT connectors have a soldering peg attached to a housing with an array of contacts. Such SMT connectors with a soldering peg are fixed to a circuit board by soldering the soldering peg to a pad on the surface of the circuit board. However, when the connector is mounted on the circuit board, if the tine parts of the contacts protrude beyond the soldering part of the soldering peg, the connector is inadequately fixed to the circuit board. On the other hand, if the soldering part of the soldering peg protrudes beyond the tine parts of the contacts, the connector cannot be electrically connected to the circuit board, although it can be fixed to the circuit board.
To overcome the problem of alignment of the tine parts of the contacts and the soldering part of the soldering peg when the connector is mounted on the surface of the circuit board, an SMT connector having a soldering peg capable of moving with respect to the surface of the circuit board is suggested in Japanese Utility Model Laid-Open No. 5-23429, for example. A connector assembly having a pair of SMT connectors is described, in which each connector has soldering pegs disposed in a movable manner at the longitudinal ends of the housing thereof.
When paired connectors are connected to each other, it is desirable that the operator can perceive that the connectors are correctly connected to each other. The SMT connector pair described above does not have any mechanism that allows the operator to perceive the correct connection of the connectors. However, there has been proposed another connector pair having a mechanism that allows the operator to perceive that the connectors are correctly connected to each other in Japanese Patent Laid-Open No. 4-43579, for example. Here, a pair of connectors each having plural contacts is described, in which the contacts of one connector have an inward protrusion that protrudes inwardly, and the contacts of the other connector have an outward protrusion that protrudes outwardly and is formed at a resilient part of the contact which can be deflected inwardly. In this connector pair, when connecting the connectors to each other, if one of the connectors is inserted to the other, than the inward protrusions and the outward protrusions come into contact with each other before the connection process is completed. If the insertion is continued, the inward protrusions and the outward protrusions which are in contact with each other interact, and the resilient parts of the contacts on which the outward protrusions are formed are deflected inwardly. Then, the insertion is further continued, and when the connection process is completed, the resilient parts of the contacts with the outward protrusions, which have been deflected inwardly, return to their original positions, and a tactile response is produced. By feeling the tactile response, the operator can know that the connectors are correctly connected to each other.
In recent years, however, downsizing of connectors has been severely required, and to meet the requirement, the connectors have been made thinner. If the mechanism that produces a tactile response described in Japanese Patent Laid-Open No. 4-43579 is used for a low-profile connector assembly, the beam of each contact cannot have a sufficient length. Thus, the contact has a smaller deflection when the connectors are connected to each other, so that an adequate tactile response cannot be produced. In addition, in order to maintain the electrical connection between the contacts with the connectors being connected to each other, the resilient part of the contact having the outward protrusion is designed to return to a state just short of the original state even after the paired connectors are completely connected, so that the resilient part still has some resilient force. The strength of the tactile response produced when the paired connectors described are completely connected depends on to the extent that the resilient part of the contact returns. Thus, if the resilient part has to have some resilient force even after the paired connectors are completely connected, the resilient part cannot return to an adequate extent, so that an adequate tactile response cannot be provided.